Tài liệu động lực học ô tô tiếng anh

Tài liệu động lực học ô tô tiếng anh Tài liệu động lực học ô tô tiếng anh Tài liệu động lực học ô tô tiếng anh Tài liệu động lực học ô tô tiếng anh Tài liệu động lực học ô tô tiếng anh Tài liệu động lực học ô tô tiếng anh Tài liệu động lực học ô tô tiếng anh Tài liệu động lực học ô tô tiếng anh Tài liệu động lực học ô tô tiếng anh Tài liệu động lực học ô tô tiếng anh Tài liệu động lực học ô tô tiếng anh Tài liệu động lực học ô tô tiếng anh Tài liệu động lực học ô tô tiếng anh Tài liệu động lực học ô tô tiếng anh

3 rd Edition MOHD AZMAN ABDULLAH JAZLI FIRDAUS JAMIL AHMAD ESMAEL MOHAN VEHICLE DYNAMICS MODELING & SIMULATION MOHD AZMAN ABDULLAH JAZLI FIRDAUS JAMIL AHMAD ESMAEL MOHAN To cite this book: M.A Abdullah, J.F Jamil, A.E Mohan, Vehicle Dynamics Modeling & Simulation, Malacca, Centre for Advanced Research on Energy (CARe), Faculty of Mechanical Engineering, Universiti Teknikal Malaysia Melaka, ISBN 978-967-0257-78-5, 2016 First published 2016 (27th September 2016) Copyright © 2016 by Centre for Advanced Research on Energy (CARe) All rights reserved No part of this publication may be reproduced, stored in a retrieval system, or transmitted, electronic, mechanical photocopying, recording or otherwise, without the prior permission of the Publisher Reprinted 2018 (2nd Edition) Edited and Reprinted February, 2019 (3rd Edition) ISBN: 978-967-0257-78-5 Published and Printed in Malaysia by: Centre for Advanced Research on Energy, Faculty of Mechanical Engineering, Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya 76100, Durian Tunggal, Melaka, MALAYSIA Fax: +6062346884 | Email: care@utem.edu.my As part of anti-plagiarism policy, we hereby acknowledge all various sources of facts and figures that we used in this book to give the understanding to the students Most of the facts and figures we could not find the sources We would like to thank all legal owners of the facts and figures Mohd Azman Abdullah | mohdazman@utem.edu.my, mohd.azman@gmail.com This book is not for sale You may donate minimum of USD 7.00 to the author as a token of appreciation for compilation of the notes And/or at least cite this book in your publications Link for donation: https://www.paypal.me/MAAbdullah CONTENTS Introduction 1.1 Dynamics of Vehicle 1.2 Tire Axis System 1.3 Vehicle Modeling Vertical Vehicle Dynamic Modeling And Simulation 2.1 Introduction 19 2.2 1DOF Quarter Car Model 20 2.3 2DOF Quarter Car Model 23 2.4 2DOF Bounce and Pitch Model 30 2.5 4DOF Pitch Plane Ride Model 31 2.6 4DOF Roll Plane Ride Model 32 2.7 7DOF Full Car Ride Model 32 Lateral Vehicle Dynamic Modeling And Simulation 3.1 Introduction 37 3.2 Lateral Vehicle Kinematic Model 37 3.3 Steady-State Handling Characteristics 47 3.4 Influence of Vehicle Parameters on Handling Characteristics 43 3.5 Roll Dynamics 57 3.6 Example 2DOF Lateral Model of Handling System with Disturbance 61 Longitudinal Vehicle Dynamic Modeling And Simulation 4.1 Introduction 73 4.2 2DOF Longitudinal Vehicle Dynamics Model 73 4.3 7DOF Longitudinal Vehicle Dynamics Model 81 4.4 Powertrain Dynamic Modeling 84 Tire Dynamic Modeling And Simulation 5.1 Introduction to Tire Forces and Moments 91 5.2 Tire Structure 93 5.3 Tire Rolling Resistance 94 5.4 Longitudinal Tire Force 96 5.5 Lateral Tire Force 98 5.6 Aligning Moment 106 5.7 Dugoff’s Tire Model 108 5.8 Magic Formula Tire Model 110 5.9 Calspan’s Tire Model 113 5.10 Interpolation Tire Model 118 Mechanical System Modeling Tutorial Using Matlab 6.1 Introduction 121 6.2 Matlab Coding 121 6.3 Script File 122 6.4 One Degree of Freedom (1DOF) System 126 6.5 Analysis at Different Parameters 130 6.6 Two Degree of Freedom (2DOF) System 134 10 Vehicle Dynamic Modeling Tutorial Using Matlab/Simulink 7.1 Introduction 145 7.2 One Degree of Freedom (1DOF) System 145 7.3 Simulink Model Subsystem 160 Vehicle Dynamic Simulation Tutorial Using CarSim 8.1 Introduction 167 8.2 Simulation 168 8.3 Simulation at Different Parameters 173 Vehicle Dynamic Modeling Verification Tutorial 9.1 Introduction 183 9.2 4DOF Vehicle Dynamic Roll Model 183 9.3 Chassis Twist Road Simulation 194 9.4 Data Processing in Matlab 198 9.5 Model Verification 203 Modeling and Simulation of Vehicle Adaptive Cruise Control 10.1 Introduction 211 10.2 Methodology 211 10.3 Simulation Results 227 References 237 CHAPTER INTRODUCTION 1.1 Dynamics of Vehicle The dynamics of vehicle can be modelled and simulated for the purpose of study and analysis The dynamics behaviours of the vehicle are also can be observed through simulation This method in analysing and studying the dynamics performances of vehicle via simulation are due to the constraints (cost, time and safety) of other approaches such as actual vehicle experiment Vehicle can be classified to ground, fluid and inertia vehicles Ground vehicles are supported by the ground with maximum speed of 600 km/h, guided with constrained to move along a fixed path example railway vehicle (Fig 1.1) and tracked levitated vehicle and non-guided (Fig 1.2) where the vehicle can move in any direction on the ground example road and off-road vehicles Fluid vehicles can be operated to the maximum speed of 3,000 km/h example marine craft (Fig 1.3), hydrofoils and ships that move on and under water Inertia vehicles can be operated to the maximum speed of 50,000 km/h, example aircraft (Fig 1.4) and spacecraft Fig 1.1: Guided ground vehicle Fig 1.2: Non-guided ground vehicles Fig 1.3: Fluid vehicle Fig 1.4: Inertia vehicle The vehicle dynamics system interaction (Fig 1.5) consists of the inputs such as visual (from the driver of camera), ground elevations and surface irregularities which interact with the tires and aerodynamic loads which act on the body The driver may apply inputs for direction through steering system and acceleration and braking through gas and brake pedal respectively The driver behavior is also can be modelled for simulation purposes The outputs evaluation of the vehicle are measured in term of performance, handling and ride Fig 1.5: Vehicle dynamics interaction In fundamental approach to vehicle system modeling, vehicle dynamics is concerned with movement of vehicles The movements include acceleration, braking, ride & cornering The vehicle dynamic behavior is determined by the forces imposed on the vehicle from the tires, gravity, and aerodynamics The vehicle and its components are studied to determine what forces will be produced by each of these sources at a particular maneuver and how the vehicle will respond to these forces For that purpose it is essential to establish a rigorous approach to modeling the systems and the conventions that will be used to describe motions In the lumped mass vehicle analysis, a vehicle is made up of many components distributed within its exterior envelope For most of the analysis on vehicle all components are assumed to one together For example, under braking, the entire vehicle slows down as a unit; thus it can be represented as one lumped mass located at its center of gravity (CG) with appropriate mass and inertia properties For longitudinal vehicle & lateral motions (acceleration, braking and cornering), one mass (total vehicle mass) is sufficient For vertical vehicle motion, vehicle body (sprung mass) is treated as lumped mass and wheel (unsprung mass) is treated as another lumped mass The basic vehicle axis system (Fig 1.6, Table 1.1) consist of translational motions and moments which are the longitudinal motion through x-axis where the direction to the front of the vehicle is the positive value, the lateral motion through the y-axis where the direction to the right side of the vehicle is the positive value, the vertical motion through z-axis where the upward direction is the positive value, the roll moment about the x-axis where clockwise direction is positive, the pitch moment about the y-axis where clockwise is positive and the yaw moment about the z-axis where clockwise direction is positive LongitudinalVehicleDynamics/User interface : with controller throttle 80 60 40 20 brake 80 60 40 20 0 Time (sec) 10 Fig.10.17: Throttle input and braking input 10.3 Simulation Results Before come out with actual result, first we should determine what expected result will be shown in the simulation that has been develop whether the result is obeying the standard graph of longitudinal velocity versus time or otherwise Fig.10.18: Standard graph for longitudinal velocity versus time (Stanford, 2003) 227 Actual result of Longitudinal Vehicle Dynamic body Based on the graph shown, the result obtained is obeying the standard longitudinal vehicle dynamics graph plotted During the throttle pedal is press by the driver, the vehicle start to accelerate which is shown in first line, then, when the driver maintaining the pressure on throttle pedal, the vehicle move with constant velocity as shown in straight line above in the graph Next, when the driver release the throttle pedal, vehicle start to decelerate as shown in the third line from the graph, and lastly, the vehicle move with constant velocity until it stop at some time Therefore, as the result obtain parallel with the standard founding, next process toward validating the result with existing result that be found in another software called CarSim will be conduct Signal Value of Longitudinal Vehicle Model Longitudinal Velocity, Vx 0 200 400 600 800 1000 1200 1400 Time, t Fig.10.19: Result graph obtain of longitudinal velocity versus time Verification of longitudinal vehicle dynamics in Matlab/SIMULINK with CarSim CarSim is a commercial software package that predicts the performance of vehicles in response to driver controls (steering, throttle, brakes, clutch, and shifting) in a given environment The using of CarSim in this project is to comparing the value and the shape of graph that should tally with the given condition in CarSim After select the procedure and the vehicle configuration, the result will be produce as the plot button is click as shown in Fig 10.20 Then, the result will come out with various type of plotting, hence we should choose the correct plot as shown in below figure 26 with our desired graph to compared 228 Fig.10.20: Vehicle loaded condition class D/sedan with procedure of acceleration and braking condition Fig.10.21: Graph of longitudinal speed, Vx versus time, t obtain to compare with the Simulink result 229 Torque tracking control result (Engine dynamics and transmission control) (Nm) The result coming from the engine dynamics model is obtain as follow; Fig.10.22: Engine torque-speed curve The engine torque map represents the torque delivered by the engine as a function of engine speed and engine throttle position The engine torque map is used to position the engine throttles to match the drivers’ torque demand The first column corresponds to time; the second column corresponds to throttle opening in percent In this case no brake is applied (brake torque is zero) The vehicle speed starts at zero and the engine at 1000 RPM Fig 10.23 shows the plot for the baseline results, using the default parameters As the driver steps to 60% throttle at t=0, the engine immediately responds by more than doubling its speed This brings about a low speed ratio across the torque converter and, hence, a large torque ratio The vehicle accelerates quickly (no tire slip is modeled) and both the engine and the vehicle gain speed until about t = sec, at which time a 1-2 upshift occurs as shown in figure 28 The engine speed characteristically drops abruptly, then resumes its acceleration The 2-3 and 3-4 upshifts take place at about four and eight seconds, respectively Notice that the vehicle speed remains much smoother due to its large inertia 230 Vehicle Speed (km/h) Transmission shift points Throttle (%) Fig 10.23: Automatic transmission shift point A shift control device for an automatic transmission determines an upshift and a downshift of gears according to a gear shift map (gear shift schedule) based on the vehicle speed and the accelerator pedal operation amount (or the throttle opening degree According to the gear shift determination based on the vehicle speed and the accelerator pedal operation amount (or the throttle opening degree), the gears are shifted based on accelerator pedal operations according to the driver's intention a first gear change determination section that determines whether the automatic transmission should change gear based on a vehicle speed and an accelerator pedal operation amount or based on the vehicle speed and a throttle opening degree and a second gear change determination section that determines whether the automatic transmission should change gear based on the vehicle speed and a load on an internal combustion engine or based on the vehicle speed and a required drive force of the vehicle, where the first gear change determination section is used to determine whether the automatic transmission should downshift and the second gear change determination section that is used to determine whether the automatic transmission should upshift However, gear shift determination based only on the load of the internal combustion engine and the drive force does not allow the gear shift operation of the automatic transmission to reflect the driver's intention based on accelerator pedal operations 231 Brake dynamics In the Fig 10.24, it can be observed that the wheel locks up in about seven seconds The braking, from that point on, is applied in a less-than-optimal part of the slip curve That is, when slip = 1, as seen in the lower plot of Fig 10.25, the tire is skidding so much on the pavement that the friction force has dropped off This is, perhaps, more meaningful in terms of the comparison Usually, the curves will not exactly pass the origin due to rolling resistance, inaccuracies in tire Clearly, the longitudinal tire force is close to being proportional to the tire load but not quite The peak value is the optimal value to brake, but just beyond the slip corresponding to this optimal value, the wheel will lock in very short-time The distance traveled by the vehicle is plotted for the two cases Without ABS, the vehicle skids about an extra 100 m, taking about few seconds longer to come to a stop Longitudinal Slip With ABS Without ABS 0.9 Longitudinal slip 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 10 10 Time, t (s) Fig 10.24: Result of longitudinal slip Stopping Distance 900 Stopping distance, (ft) Stopping Distance, (m) 800 Without ABS With ABS 700 600 500 400 300 200 100 0 Time,t (s) Fig 10.25: Result of stopping distance It is apparent that deceleration and the tire-road coefficient of friction has a great effect on the braking torque required A slight change in friction can have a large effect on the braking torque In reality the braking torque requirements will be lower because of various factors Bearing friction, rolling friction, wheel slip, and non-liner deceleration 232 lower the torque requirements In Fig 10.26, deceleration is assumed to be constant without ABS, however in reality it is not the case A factor that lowers the actual torque required by the rear axle is wheel slip However, the brake force can only increase to the limit of the friction coupling between the tire and road The friction coupling depends on some small amount of slip occurring between the tire and the road Various deformation processes cause braking force and slip to be coexistent The plot in Fig 10.27 shows the wheel angular velocity and corresponding vehicle angular velocity This plot shows that the wheel speed stays below vehicle speed without locking up, with wheel angular speed going to zero in less than seconds This model shows how you can use Simulink to simulate a braking system under the action of an ABS controller Brake torque 1500 Brake Torque, (Nm) 1000 500 0 Time,t (s) 10 Fig 10.26: Result of brake torque Angular Speed 80 With ABS-wheel angular speed With ABS-vehicle angular speed Without ABS-wheel angular speed Without ABS-vehicle angular speed 70 60 Angular speed, (rad/s) Brake tprque, (lbf.ft) With ABS Without ABS 50 40 30 20 10 0 Time,t (s) 10 Fig 10.27: Result of angular speed 233 Adaptive cruise control simulation result After connecting the PID controller on the model, the simulation was run and the graph as shown in Fig 10.28 is obtained Based on the Fig 10.28, the blue line shows the distance between two vehicles and the red is the speed of the leader vehicle and green is the speed of the follower vehicle The ACC vehicle approaches the target vehicle at its sett speed for example in this graph 70 km/h ACC system senses the impeding vehicle and take action automatically adjusting the ACC vehicle’s speed to match the target vehicle speed If the ACC vehicle loses its target for example during a lane change, then the ACC vehicle will automatically reaccelerate to its 70 km/h set speed Longitudinal speed, (km/h) Adaptive Cruise Control Time, s Fig 10.28 Adaptive cruise control (ACC) result Conclusion As a conclusion, the longitudinal vehicles dynamics model is built and simulation of vehicle model is done by using MATLAB Simulink and the validation of Simulink model with CarSim is succeed As a conclusion adaptive cruise control (ACC) system are capable of automatically maintaining a constant inter vehicle distance and speed, which are desired by the driver Therefore, according to the result of the system developed it shows that the simulation of the system is successfully obey the concept that preceding vehicle is safely followed in front of the vehicle in certain speed (same speed) with safe distance between the vehicles according to its condition For further research, beside interaction with driver, interaction between other vehicles can also be defined for better friendly-driving environment 234 235 236 REFERENCES Pacejka, H (2005) Tire and vehicle dynamics Elsevier Gillespie, T D (1997) Vehicle Dynamics Warren dale Genta, G (1997) Motor vehicle dynamics: modeling and simulation (Vol 43) World Scientific Rajamani, R (2011) Vehicle dynamics and control Springer Science & Business Media Cho, D., & Hedrick, J K (1989) Automotive powertrain modeling for control Journal of dynamic systems, measurement, and control, 111(4), 568-576 Sharp, R S., & Crolla, D A (1987) Road vehicle suspension system design-a review Vehicle System Dynamics, 16(3), 167-192 Setiawan, J D., Safarudin, M., & Singh, A (2009, November) Modeling, simulation and validation of 14 DOF full vehicle model In Instrumentation, Communications, Information Technology, and Biomedical Engineering (ICICI-BME), 2009 International Conference on (pp 1-6) IEEE Sulaiman, S., Samin, P M., Jamaluddin, H., Rahman, R A., & Burhaumudin, M S (2012) Modeling and validation of 7-DOF ride model for heavy vehicle Proc of ICAMME Canudas-de-Wit, C., Tsiotras, P., Velenis, E., Basset, M., & Gissinger, G (2003) Dynamic friction models for road/tire longitudinal interaction Vehicle System Dynamics, 39(3), 189-226 Captain, K M., Boghani, A B., & Wormley, D N (1979) Analytical tire models for dynamic vehicle simulation Vehicle System Dynamics, 8(1), 1-32 Fauzi, A., Khisbullah, H., Zulkiffli, A K., Zakaria, M M N., & Md Radzai, S (2009) Experimental evaluation of vehicle dynamics in longitudinal direction Kadir, Z A., Hudha, K., Nasir, M Z M., & Said, M R (2008, March) Assessment of tire models for vehicle dynamics analysis In Proceedings of the International Conference on Plant Equipment and Reliability (pp 27-28) Abdullah, M A., Jamil, J F., Ismail, N., Nasir, M M., & Hassan, M Z (2015) Formula varsity race car-Roll dynamic analysis Proceedings of Mechanical Engineering Research Day 2015, 2015, 23-24 237 Abdullah, M A., Ibrahim, M., Abdul Rahim, M A H (2017) Experimental and Analysis of Vehicle Dynamics Performance based on Driving Behavior Journal of Mechanical Engineering, 193-206 Abdullah, M A., & Abdul Rahim, M A H (2016) Driving behaviour analysis of young vehicle drivers Proceedings of Mechanical Engineering Research Day 2016, 2016, 19-20 Abdullah, M A., Jamil, J F., & Salim, M A (2015) Dynamic performances analysis of a real vehicle driving In IOP Conference Series: Materials Science and Engineering (Vol 100, No 1, p 012017) IOP Publishing Jamil, F M., Abdullah, M A., Ibrahim, M., Harun, M H., & Abdullah, W W (2017) The dynamic verification of vehicle roll dynamic models using different software’s Proceedings of Innovative Research and Industrial Dialogue 2016, 1, 135-136 238 239 240 27th September 2016